At the end of a session, saving the file feels like finishing the handover. Tomorrow, the file opens exactly where it was left. The thought that was supposed to go with it is harder to recover.
A stopping note can be shorter than a summary. Its job is to make the first few minutes back at the desk less uncertain.
Write the next question.
“Continue the introduction” still asks the next person to reconstruct the task. “Check whether the first paragraph explains who the reference index is for” gives them something to read for.
That question might turn out to be the wrong one. It is still a more useful starting point than an unlabelled cursor.
Leave the uncertainty attached.
If a choice is provisional, say which part is provisional. If a section is waiting on another document, name it. A reader should not have to infer the status of a whole project from a half-written sentence.
The note can live at the top of the working file until it is answered. Once the work moves on, delete it or move the decision into the project record.
Before closing the file, leave one question worth opening it for.